Transmission of sound and conversation



Aug. 10, 1943.

F. ROBERTS ETAL TRANSMISSION OF SOUND AND CONVERSATION F iled Oct. 23, 1942 l v g BY F o HTTORN V.

IN VEN TORS.

Babe/'73 Patented Aug. 10, 1943 I This invention relates to a system, forthe transv cei'vingstation.

' mission of sound impul'ses of th'e;aforementioned" pulse pick-up and spechpick-up element;

. V w r i TRANSMESSION on SOUND AND v convnnsnrlon w a antennae; and Arthur W. Bennett? Kansas City,fMo. f; L ,4 c,

ippiica tionctobe1 '23, 1942;. Seri'aL 51114635086 n V V w v, crating communicating systemsoverwhich-Morse mission oftalking impulses and otherwave forms, and continental code' may-befsent and received; I

such as teles aphy: or power impulses, and has and over which speechmayibe sent and received,

for its primary object the provision o f meansafor are found intheunitarylc'ommunicator made-in transmitting intelligibies'oundeither through the accordance withourinventionnln addition to.

employment of Morse cod-e,{continental' codejor suchsqualificationspthecombinationof thecomfthe voice over land lines or similar conductors, ponent sub systems'withinthe compact c'onirnuall of which impulses are boosted by an audio nicator a-t one-fend "of the transmission: line or amplifier forminga part o'f the self-contained lines are capable of producing highly efilcient re-- I instrument disposedatthetransmittingor re ioflsults and of maintainingproperand adequate v v a v V power atkallsettings of the 'switches'and su f 1 one of the primary o'bjeqtso-i the instant in 1 ficient amplification properties to send thejiin-f vention is to 'provi-de'bav compact transmitting pulses of 'both code and speech character over" and receiving station ior code, power or iv 'ce long'lines without auxiliary-boosting. impulses, that ,constitutesacomposite systemin- The wiringdiagra I illustrated inthe acoorneluding amplifying meanscommon tothefappa-g panying drawing, embodies one form of theiine T ratus for transmitting co de, powerlor voice imvention and shows in grouped arrangementthe pulses and capable of being operably "associated apparatus formingthe c'omposite system of sound with the apparatus inuse by a systemiof switches; and conversation where the .severalfimpulses caf' I Thisinvention hasff or cajyet. further aim the pable of being handled by the systern are' imjl j provision of a composite system; for the, transpressedon a line commonjtobo th'the code im-' character having; as a component part thereofj" Because alternating current "is universallyl'- a means forsupplyin g'tpower to theappar'atusfor available and usually; supplied throughffeedei V transmitting Morse code, continental ccda'and' linesj such as indicated by the-numerals 2 and =1 speech impulses which souroe'of'poweris brought 4', conduitsfi' and 3 are]joinedit saidlines'2 and into operative relation'with the selected annal land supplycurrent-totransformer"'tzjwhen ratus'through a unique switch system ithe' char switch'f H3 is closed This transformer raises and} acter of which insures theemployment' ofjthe rectifiesthegalternating current from supplyline'si aforesaid audio amplifying apparatus; to the end 2 and 4 iniorder thatv proper plate and filament 7 r that code, power or speechimpulses may be sent voltages maybe impressed upon the'component along a conductingline crimes for greati-dis units of the-system, Rectifiertube-M forms a tances-without the necessity of using the relapart ofthe power jsupply and conventio'nalf filter' tively large number of parts that must now he choke l6 and condensers i8 andjwjareiin circuit;

, employed when a station is equipped to transmit 3a with transformer-t2" and tube 'l d 1A bleeder re-f and/or receiveimpulses 'ofthe three characters 'sistor ZZ'is alsofncircuit to insurecorrect"load-{ aforesaid. i-ng of'thepjowersupply unit. T i

vide a system for the transmission of sound and impulses is a part of the apparatus when assemy' A yet further aim of this invention isto pro The means for-impressing telegraphybr case 1 I conversation that .has means for both 'trans-' 'bled for use atfa station and may be made ren Y mitting and receiving telegraphic and talking tively small and to include parts joined 'to' the],

amount of eifort and the use of a relatively small impulses, and that maybe manipulated toserve power supply by interconnecting terminals 24and as a transmitter or receiver with 'a minimum 26 with terminals 28 and 3!) of the power pack;

A housingynot here fully illustrated, i pref 5; group of elements. V p erably supplied to establish asound chamber 32 Heretofore, it has been the commercial practo contain a'small, sound pick-up or transmitter I tice to use separate instruments for the trans- 34 in juxtaposition to zrteleg'raph s n 3 tems have separate lines of communication for ated by'theoperator. This key tais-removably mission of Morse code, continental, code, and 7 When the latter is operated; itssou'n'd will'beo c. speech. Even at the present time railroad sys-. picked-up by "transmitter 34-as key 13's ;is act l e the transmission of code and speechfimpulses, I included in circuit through the medium of a coni and in such systems is to be found'many parts, ventional jack 40 and a group of 'f 'rj e; the function of allof which is found in the com v throw, "double-pole switches constructed fora municating system embodying this invention. simultaneous operation and as a; unit, maybe; All the desirable qualifications of perfectly opmounted on the housing which contains the Other parts ofthis portilon of th system.;: These by talking-into receiver I21. r

- continental code.

switches-are designated by thenumerals 42, 44 48 and 48 respectively and when manipulated,

2,326,253 f V i F1; 75411 Switch is closed .to connect the system to supply 1ines:2 and 4. Pilot light Hi8 serves to Q r visibly indicate to theoperatorthat the system permit directingof the code impulses or the talk- 7 ing impulses into lines:ll 2 or 4 for transmission' to a remote point; vFor example, when code impulsesfover thetransmission lines ,.but

' when the switches are in the 'lotherone' of the I two possible positions, voice impulses may be sent.

' Amplification of all impulses occurs through switches .42, 44,16 and 48 are in orieposition, key 38 may be used to send Morse or continental s is joined toa 'source'of current supply.

Switch Hfl is lgnowninthe artias a break-in switch-arid is manipulated by the operator to change transmission lines H2 or I ll when the receiving operator at the remote end of thef'said lines interrupts for'some reason, such as to request a repeat. Speaker lll'i'deliver v the message from the operator at the remote end of the transmission lines to the operator near this speaker. when the remote operator breaks-in to themedium of the audio amplifier, which comprises'tubes' 50 and 52 that receivetheir power.

supply from the source above described. i-.Con'-,

nection is made between tubes 50 and 52 by suitablyjoining terminal 54 of the powerfsupply with terminals 58 and (50 of tubes 59 and 5Z;respectively. Terminal 56 of the power unit and one Htermi'nal of each; tubes 50 and 5 2,a1jc grounded to complete the circuit in an obvious manner j,

" An input transformer 62 is joined to -tube 58 through themedium oi potentiometer 54 and .an output transformer 66-joined togtube 52 inserted to control thevolume of current toathe transmission lines'and tomatchthe impedance to those lines. Headphones, not here shownbjrnay be connectedtothis amplifying unit by a-p'none jack 68." i

dens ors necessary for their proper operationall of which are understandably illustratediintthe" drawing and will not here be further described for their function and presence in an audio amplifier is. Well-knownin the arts This-amplifying unit is connected withswitches 42; 4,4, 45 or 48 as the case may be, to insure thetboosting-or amplifying of impulses when they are sent over. the system regardless of whether they be offthe Morse, con-c tinental codes, or speech'type. 1 The manner inwhi h each positionoi the said :switches is related to the-sending oi code or' speech impulses is above described: When con- 1 't'inental code, in the natur flcfertelegraphy or power impulses isbeingused the; remaining parts 7 of the system illustratedarebrought into play.

Apre-amplifier tube 18' and a rectifier and am plifier tube 12 are in circuit shown, ;and are combined with an AC line voltage droppingre-;

signal back. The matching transformer H8 is necessaryto. the operation of speaker H6.

'IheL four double pole double throw switches I, I22, I24 and I have two positions. In one position, the receiver I2! is cut into the system for use as a receiverof talking impulses while in the other position, the receiver l2! becomesa speaker throughwhich the operator hears spoken words ,comingfromfa remote point ;over the y 2 H1, Tubes 5 0 and 52 having resistors and core sistor 14, choke -16, and condensors, 18 and 88.

Condensors32, 84, 86'and'83areofthe fixed type while resistorsfifl, 9:2, 94,,96, 98, 00 and-I92 combine with choke I64 for the intended operas jtionoi the unit and with transformerlpfi for the 7 matching of the circuit.- ,Key. 38 isused when this unit is'being employed for the sending of:

transmission lines. leading to the instrument. Iransior'mer' I28'is necessary in-matching. j

The switching system shown-insures that the impulses'leaving the system are all boosted or 'amplifiedior distance. I i

The illustrated embodiment of the-invention is schematically'shown and since it is realized that circuits having vdiirerent characteristics and substitute parts may be employedtoaccomplish the-broadobjects of this invention, it is desired tobelimited only. by thescope oi the appended claim.

Having thus described the. invention, what ,is

either the means for impressing talking im}. pu1ses, the means forimpressing the telegraphy impulses or the means foriim'pressing the power impulseslon the said line; and a power supply unit for the saidseveral impulse impressing means,'jthe said switching system being adapted V to supply current to-the selected impulse impressingmeans from said power supply unit.

" FRED ROBERTS.

ARTHUR W. BENNETT. 

